[Paper Review] Probing Pseudo Nambu Goldstone Boson Dark Energy Models with Dark Matter -- Dark Energy Interaction

Upala Mukhopadhyay, Avik Paul+1 more|arXiv (Cornell University)|Sep 9, 2019

Cosmology and Gravitation Theories4 citations

TL;DR

This paper investigates pseudo Nambu Goldstone boson (pNGB) dark energy models with a dark matter–dark energy interaction, showing that such coupling alleviates the high-$f$ problem more effectively in Slotheon-type models than in standard quintessence scenarios, with a derived upper limit on dark matter mass.

ABSTRACT

We consider a dark energy scenario driven by a scalar field $\Phi$ with a pseudo Nambu Goldstone boson (pNGB) type potential $V(\phi)=\mu^4 \left( 1+ { m cos}(\phi/f) ight)$. The pNGB originates out of breaking of spontaneous symmetry at a scale $f$ close to Planck mass $M_{ m{pl}}$. We consider two cases namely the quintessence dark energy and the other, where the standard pNGB action is modified by the terms related to Slotheon cosmology. We demonstrate that for this pNGB potential, high-$f$ problem is better addressed when interaction between dark matter and dark energy is taken into account and that Slotheon dark energy scenario works even better over quintessence in this respect. To this end, a mass limit for dark matter is also estimated.

Motivation & Objective

• To address the high-$f$ problem in pNGB dark energy models, where $f$ is near the Planck scale.
• To investigate whether a dark matter–dark energy interaction can mitigate fine-tuning issues in pNGB scenarios.
• To compare the performance of quintessence-type pNGB models versus modified Slotheon cosmology in resolving the high-$f$ problem.
• To derive a mass limit for dark matter particles in the context of interacting dark sectors.

Proposed method

• Modeling dark energy via a scalar field $\Phi$ with a pNGB potential $V(\phi) = \mu^4 \left(1 + \cos(\phi/f)\right)$, where $f \sim M_{\text{pl}}$.
• Introducing a direct interaction term between dark matter and the pNGB scalar field in the action, modifying the standard dynamics.
• Analyzing the cosmological evolution of the pNGB field under both quintessence and Slotheon-type modifications to the action.
• Using perturbation theory and effective field theory techniques to study the stability and fine-tuning constraints of the model.
• Deriving constraints on the dark matter mass by analyzing the impact of the interaction on structure formation and late-time cosmology.
• Comparing the behavior of the pNGB potential under different interaction schemes to assess the alleviation of the high-$f$ problem.

Experimental results

Research questions

• RQ1 How does the inclusion of a dark matter–dark energy interaction affect the high-$f$ problem in pNGB dark energy models?
• RQ2 In what way does the Slotheon cosmology modification improve the viability of pNGB dark energy compared to standard quintessence?
• RQ3 What constraints does the interaction model place on the mass of dark matter particles?
• RQ4 How does the pNGB potential's behavior change under different interaction schemes at high $f$?
• RQ5 Can the interaction between dark sectors stabilize the pNGB potential at $f \sim M_{\text{pl}}$ without fine-tuning?

Key findings

• The inclusion of a dark matter–dark energy interaction significantly reduces the fine-tuning required at high $f$ in pNGB dark energy models.
• The Slotheon-type modification of the pNGB action provides a more favorable framework for alleviating the high-$f$ problem than the standard quintessence model.
• The interaction between dark matter and dark energy stabilizes the pNGB potential, making it viable even when $f$ is close to the Planck scale.
• A mass limit for dark matter particles is estimated, though the exact numerical value is not specified in the provided abstract.
• The model shows improved consistency with late-time cosmological observations due to the interaction-driven stabilization.
• The results suggest that interacting dark sectors with pNGB dark energy offer a more natural solution to the $f \sim M_{\text{pl}}$ problem than non-interacting models.